Read the following paragraphs and answer the question.
It began as just another research project, in this case to examine the effects of various drugs on patients with a severe mood disorder. Using an advanced brain scanning technology—the clumsily named echo-planar magnetic resonance spectroscopic imaging (磁共振光谱成像) procedure, or EP-MRSI -researchers at Boston’s McLean Hospital scanned the medicated and unmedicated brains of 30 people with bipolar disorder in order to detect possible new treatments for the more than 2 million American adults who suffer from the disease.
The project described in this paragraph aimed at finding（ ）.
A.正确答案Dwho had bipolar disorder
B.what improved people’s moods
C.whether magnetic scanning was a treatment for depression
D.how patients with a mood disorder responded to certain drugs
